I don't know why I did so well at Portal; I usually get stuck badly in FPS games and have to rely on a walkthrough.

But for some reason, Portal just clicked for me. There were a couple occasions on which I felt stymied, but I just walked away from the computer for a few minutes, torched a bowl, made a fresh cup of coffee, and it all came clear again.

I am proud to say I made it through the game in one evening and most of the next day, with no help from cheats or tips or walkthroughs or anything.

And I say this as someone who never has finished Half-Life 1, LOL. The Xan stuff at the end just stops me cold.